COVID-19 in WHO African Region: Account and Correlation of Epidemiological Indices with Some Selected Health-related Metrics

Background The coronavirus disease 2019 (COVID-19) is a highly contagious and pathogenic viral disease caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Since it was first reported in Wuhan, China, it has spread across the continents. The study is aimed at describing epidemiological indices of COVID-19 as reported by the World Health Organization and to examine correlations with some country specific measures of general health status. Methods Data from the WHO African region were extracted from World Health Organization, Global Health Security Index, Worldometer and World Bank databases, as at September 8, 2020. Other epidemiological indices were computed for the various countries. Epidemiological indices of COVID-19 were correlated with some selected health related metrics: Global Health Security index (GHSI) and current health expenditure (CHE). Pearson correlation was used to access the relationship between the health-related metrics and epidemiological indices. Results Forty-seven (47) countries belonging to the WHO African region were evaluated. A total of 1,086,499 confirmed cases and 23,213 deaths were recorded giving a fatality rate of 2.1%. South Africa recorded the highest cumulative confirmed cases as well as deaths (Cases: 639,362; Deaths: 15,004) while Seychelles (Cases:135) and Eritrea/Seychelles (Deaths:0) had the least cumulative cases and deaths (135;0 and 330;0), respectively. South Africa recorded the highest attack rate (1127.67/100,000) while Republic of Tanzania recorded the least attack rate (0.78/100,000). The highest case fatality rate/ratio was observed in Chad (7.60%) while the least value was observed in Seychelles (0.0%). France was the most common country involved in travel history of index cases. Sporadic transmission was recorded in 3 countries, 9 countries had cluster of cases while the rest had community transmission. The first WHO African region country to record COVID-19 case was Algeria, while Comoros was the last. Significant positive correlation was found between COVID-19 case number/deaths and Global Health Security Index. Conclusion The WHO African region has had its own share of the pandemic with all the countries being affected. The trio of cluster cases, sporadic and community transmission were recorded with majority being community transmission.


INTRODUCTION
The Coronavirus disease 2019  caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has metamorphosed into global pandemic with noxious morbidity and mortality (1,2). The COVID-19 pandemic is the most pressing health care issue globally (3). At the onset of the pandemic it was broadly designated as a severe respiratory illness presenting with fever, atypical pneumonia, cough and dyspnea (4,5). However, altered sense of smell and taste have long been found to be associated with the disease (5,6). More so, a review of 77 observational studies showed a good number of patients presenting with less typical symptoms. (5,7). As of July 22, 2021, SARS-CoV-2 has been responsible for 191,773,590 infections and 4,127,963 confirmed deaths (fatality rate: 2.15%) globally with the United States accounting for 33,875,385 cases and 604,546 confirmed deaths (the highest disease burden). The stratification of the data showed that the region of the Americas are currently the epicenter of the pandemic accounting for 39.22% (75,220,757) of the confirmed cases followed by Europe that accounted for 30.54% (58,576,440) of confirmed COVID-19 cases. Then in subsequent order South East Asia, Eastern Mediterranean, Africa and West Pacific regions (of WHO Classification) accounted for 19.39% (37,191,075), 6.26% (12,000,909), 2.44% (4,688,762) and 2.13% (4,094,883), respectively of global COVID-19 cases (8). Consequently, the WHO African region is the 5 th worst hit out of the six (6) WHO regions. This study is aimed at describing epidemiological indices of COVID-19 in WHO African region as reported by the World Health Organization and to examine correlations with some country specific measures of general health status.

METHODS
Data collection: Epidemiological indices of COVID-19 up to September 8, 2020 were collected from the official dashboard of World Health Organization (WHO) (9). The cumulative confirmed cases, cumulative deaths and attack rate per 100,000 of the population, transmission pattern and percentage of all deaths were extracted while case fatality ratio was computed for each country. The population of the various countries was extracted from Worldometer (10). While the health expenditure (%GDP) was extracted from World Bank database (11), the 2019 global health security index (GHSI) was extracted from the Global Health Security index database (12). Information on index cases were extracted from center for disease control/infectious disease control centers/COVID- 19 update/COVID-19 information Hub/Ministry of Health web page of the various studied countries and WHO African region web page. The following search clauses were used: "World health organization African region+country index case"; "Country COVID-19 index case+country ministry of health"; "Country CDC"; "Country COVID-19 update dashboard". In some cases, Africa news web page (13) was used to complement the details.
Quality control on data extraction: Data used in this study were extracted by the authors. The authors were divided into two groups: A (HUO and COO) and B (DAA and IMO). The two groups independently extracted the required data based on the study design. IKU harmonized the two independent results. In few cases of disparity all the authors double checked to ratify the correct data.
The following operation definitions of terms/variables were used: Global health security index: Global health security index (GHSI) is the first comprehensive assessment and benchmarking of health security and related capabilities across the 195 countries that make up the state parties to International Health Regulations 2005. The index was intended to spur measurable changes in national health security and improve international capability to address world risk such as infectious diseases outbreak that could lead to pandemics. The GHS index relies entirely on open source information (data that the country has reported on its own or has been reported by an international entity). The index prioritizes both countries' capacities as well as existence of functional, tested, proven capabilities for stopping outbreaks source (12). Current health expenditure (%GDP): This refers to the level of current health expenditure expressed as a percentage of gross domestic product (GDP). Current health expenditure as a share of GDP provides an indication on the level of resources channeled to health relative to other uses. It shows the importance of health sector in the whole economy and indicates the societal priority which health is given measured in monetary terms. It is measured as percentage of GDP (%GDP) (14). It includes health care goods consumed each year and does not include capital health expenditure such as buildings, machinery (15).

Confirmed cases/cumulative confirmed cases:
This refers to the total number of confirmed COVID-19 infection cases within the period of study. It is represented as frequency. Deaths/cumulative deaths: This refers to the total number of deaths that resulted owing to COVID-19 infection within the study period. It is represented as frequency. Percentage of deaths: This refers to the number of COVID-19 deaths recorded in a country in relation to the cumulative COVID-19 related deaths recorded in all the countries assessed within the study period. It is represented in percentage. Attack rate / Attack rate per 100,000 of population: The index refers to the number of persons infected with COVID-19 per 100,000 of the country's population. It is represented as frequency per 100,000 of population. Case fatality rate/ratio: It refers to the proportion of people who died from COVID-19 infection among all individuals diagnosed with COVID-19 over the studied period.

Statistical analysis:
Retrieved data were analyzed with SPSS for windows, version 22 (IBM Corp Armonk, NY). Epidemiological and health related metrics were described using frequencies and proportions (percentages). Pearson correlation was used in determining association of some COVID-19 epidemiological indices with some health related cum financial metrics. The alpha value was benched at 0.05.   The detailed description of the index cases of the various WHO African Region countries studied is shown in Table 2.

Guinea Bissau
The first two confirmed cases were: a Congolese U. N. employee and an Indian citizen.

Seychelles
The two cases were Seychellois who returned from Italy.    (Table 3).   Figure 2).  (Table 5).  (16) and that of the region of the Americas, Europe and South East Asia. In contrast to the Ebola Virus disease (EVD), the CFR is far below that of EVD which had global average of 50% (even up to 90% in some places) (17) and ranged from 39.6% to 84.3% in the West African Sub-region (20). However, COVID-19 has been found to be more contagious with an average Ro value of 3, consequently cause for higher cumulative number of deaths observed (19). Since the report of the first case in the region in Algeria on February 25, 2020, seven months later the epidemic curve in the region remained flatter in comparison with region of Americas, Europe and Asia as against earlier insinuations. Before now, African has been predicted to be most vulnerable continent in terms of COVID-19 infection and was predicted as region where COVID-19 will have major impact. This prediction was based on the continent's weak health care system cum large immunocompromised population (20,21,22). However, the prediction proved otherwise. There have been varying hypothesis in attempt to explain the reason to the relatively low COVID-19 cases in African region as against expectations. Some experts attributed this to low numbers of SARS-CoV-2 introduced (seeding) into Africa possibly due to low volume of air travel to the region (23). More so, the mitigative measures (partial and complete lock down and travel restrictions) (2) may have played role. Some researchers have proposed that the greater youthful population of the African region with median age < 20 years as against Europe and the USA with medium age > 38 years (24,25) is a contributing factor. Also, some authors have attributed the low incidence to favorable climate. Sajadi and colleagues have recorded association between temperature / humidity and COVID-19 spread (26) which is in line with previously reported factors for survival in earlier epidemic: SARS-CoV and influenza (27,28,29). Africa experiences warmer and drier weather within December and April season with average temperature of the day > 20 degree Celsius (30). In a different perspective, some authors have posited that a population across Africa have some level of SARS-CoV-2 immunity as a result of prior exposure to other coronaviruses (30). Lastly, there are postulations of prospective effect of Bacilli Calmette-Guerin (BCG) vaccination against COVID-19 infection (31). However, the reports were not from clinical trials (but experimental studies) which prompted WHO to recommend disregarding the results until the clinical trials are complete (32). Alternatively, there is possibility of low report of COVID-19 cases in African region owing to lack of material resources as available in the Americas and Europe continents that are more economically buoyant. Although some of the postulations have conflicting versions, future studies would help unravel the explicit contributing factors to the relatively low COVID-19 event in African region.
In this study, we found South Africa to be the epicenter of COVID-19 pandemic in the WHO African region. As of September 8, 2020, South Africa had 639,362 confirmed COVID-19 cases, accounting for more than half (58.8%) of the pandemic in the region. Comparatively to the global data, South Africa ranked 12 th in the global burden of COVID-19 pandemic below USA, India, Brazil, Russia, Argentina, Colombia, Spain, Peru, Mexico, France and UK. Though we could not "pin -point" the exact reason for such large burden, however, some authors have argued that South Africa carries a significant burden of tuberculosis, HIV, and HIV/TB coinfection, with millions of the population on immunosuppressant drugs as well as others who are HIV-positive but not on retroviral therapy (33). South Africa still has the largest global burden of HIV (approximately 19%) (34,35). There are reports that those with comorbidities are more susceptible to developing severe COVID-19 (36). On the flip side, some authors have attributed the "sky rocketing" of the pandemic in South Africa to arrival of winter in South Africa at the start of the epidemic considering the fact that all respiratory viruses spread more effectively in winter (20).
Adjusting the COVID-19 cases per 100,000 of the population (attack rate per 100,000 of population) still showed South Africa, then Cape Verde and Equatorial Guinea at the top. South Africa alone clocked attack rate above 1000 cases per 100,000 of the population. Although Cape Verde and Equatorial Guinea do not rank among the top 10 in terms of cumulative confirmed cases, cases per 100,000 of the population were observed to be high.
South Africa accounted for majority (64.64%) of all deaths in the region followed by Algeria and Nigeria. These three were among the first four countries in the region recording COVID-19 cases on March 5, February 25 and 27, respectively. As of the time of this report, Eritrea and Seychelles were the only countries in the region without record of COVID-19 related mortality. Chad (7.60%), Liberia (6.25%) and Niger (5.86%) had the highest case fatality ratios. These values are quite far from the average CFR of the entire region and only comparable to values seen in countries in region of America and Europe such as Mexico (10.1%) and Italy (8.2%) (37). Although merely passed 1000 case profile, the case fatality rate of Chad is high and is among the highest values globally. Before the pandemic, Chad has been ravaged by malaria, Chikunguya and measles. The high incidence of measles have been attributed to insufficient vaccination (only 22% of children aged 12 to 23 months are vaccinated) (38). Inter-country comparison of CFR is an important indicator of disease characteristics and is important for both national and international priority settings as well as recognizing health system performance. However, it is pertinent to note that there are varying factors that can confound the value: undetected cases / low case detection, and delayed case reporting (39).
France was the most involved country in travel history of index cases in the region, followed by Italy and UK. A striking feature about countries that had index case with France travel history is that all except Democratic Republic of Congo and Zambia were all former French colonies. France still maintains very strong ties and less travel/visa bureaucracy with its former colonies more than their British (UK) counterpart (40).
In this study we found strong positive correlation between cumulative confirmed cases / cumulative deaths and Global Health Security Index. This observation is quite ironic in the sense that cases and deaths were supposed to be low in countries that have high GHSI and vice versa (negative correlation). This trend is also observed in global data of COVID-19 where countries with high GHSI such as USA and UK have high cumulative confirmed cases and deaths. Though we were not able to "pin point" the exact reason for this reverse trend, however, it can be inferred that countries with low human development index are less inclined to report or to put effort to get proper measures of COVID-19 cases and deaths. Nevertheless, future research and events would possibly substantiate this.
The findings of this study are potentially prone to varying limitations. First, the study took results in retrospect and the inherent limitations such as selection bias may not be ruled out. Secondly, the outcome at the time of going to press is not conclusive as the pandemic is still ongoing. Also, metric such as Global health security index (GHSI) relies on open-source information, it might be prone to bias.
In conclusion, the WHO African region has had its own share of the pandemic with all the countries being affected. The trio of cluster cases, sporadic and community transmission were recorded with majority being community transmission. Global health security index was found to be positively correlated with cumulative confirmed cases and cumulative deaths.